1. Field of the Invention
The present invention relates to an internal combustion engine control apparatus that controls an internal combustion engine mounted in a vehicle, and more particularly to an internal combustion engine control apparatus that controls an internal combustion engine, based on the coupling state of the clutch of a vehicle such as a motorcycle, a buggy vehicle, or a snowmobile.
2. Description of the Related Art
In general, an internal combustion engine mounted in a vehicle is coupled, through a clutch, with the driving device of the vehicle, such as a tire; depending on the coupling state of the clutch, i.e., the state of coupling between the internal combustion engine and the driving device of the vehicle, the rotation of the internal combustion engine may become unstable. For example, in a state (referred to also as a state where a clutch lever is being released) where the internal combustion engine and the driving device are completely coupled with each other, because the internal combustion engine is also driven by the rotating tires through the clutch, the rotation of the internal combustion engine itself is stable; however, when the foregoing state is followed by a state (referred to also as a state where a clutch lever is being pulled) where the internal combustion engine and the driving device are not coupled with each other, because the internal combustion engine is suddenly released from the drive by the tires, the rotation of the internal combustion engine may become unstable.
In general, in the control apparatus for an internal combustion engine provided with an electronic-control fuel injection device, a control unit calculates a fuel supply amount in accordance with the rotation speed of the internal combustion engine or the state of the load, and drives an injector, which is a fuel injection valve, through a control signal based on the calculation so as to control the amount of fuel to be supplied to the internal combustion engine; however, as described above, there may be a case where depending on the coupling state of the clutch, the rotation of an internal combustion engine becomes unstable; thus, to date, there has been detected the coupling state of the clutch, based on the output of a clutch switch that opens or closes in conjunction with the clutch lever (for example, refer to Patent Document 1), or there has been determined the coupling state of the clutch, based on the rotation speed of the internal combustion engine and the traveling speed of the vehicle (for example, refer to Patent Document 2), and there has been adjusted the amount of fuel injection by the electronic fuel injection, based on the detected or the determined coupling state of the clutch, so that the rotation of the internal combustion engine is stabilized.